My shop vac won't charge – any ideas?

Hey guys, I've got a DeWalt 18V cordless shop vac that I've had for about 2 years. Last week it started to take longer to charge, and now the charger light just blinks red no matter how long I leave it. Battery is the original 5Ah. Anyone else have this issue? Tried cleaning contacts but no luck.

Tim, that blinking red usually means the battery is toast or the charger can't communicate with it. DeWalt batts have a circuit board that fails sometimes. Have you tried another battery on the same charger? If it works, it's the battery. I'd get a new one – they're on sale at Home Depot right now.

Tim, before buying a new battery, check the voltage with a multimeter. If it's below 15V, the charger sees it as dead and won't charge. You can try to jumpstart it by charging with a different charger if you have one, but be careful – I've seen batteries catch fire from improper charging. Safety first!

I'm no expert by my ridgid vac did the same thing. Turned out the charger was the problem. I borrowed a friend's charger and it worked fine. So maybe try a different charger before buying a battery. Just a thought.